The present invention relates to a ski hoot which has a heel portion that pivots with respect to a toe portion while preventing relative torsional rotation. As such, the present invention is an improvement of our copending application, Ser. No. 835,038, now U.S. Pat. No. 4,677,769.
The technology developed in the skiing industry in recent times has been quite fast paced, with improvements being made to skis, bindings and the boots. One area of interest has been the interrelationship between alpine, or "downhill", skiing and a type of nordic skiing generally referred to as "telemarking". The present invention addresses needs in both of these skiing styles.
In the alpine skiing style, a rigid ski boot is locked into front and rear bindings on a relatively wide ski that is provided with cutting edges for permitting fast turns on steep downgrades. A typical alpine ski boot has a completely rigid sole and a completely rigid upper shell that extends over the foot, around the ankle and over a portion of the lower leg. Such ski boots generally do not flex so that the entire lower leg and foot of the human body is maintained in a relative unalterable configuration. Some ski boots, such as the boot shown in U.S. Pat. No. 461,103 issued 24 July 1984 to Annovi, provide a pivot between the foot shell and the ankle shell to allow limited relative movement. These hoots often utilize resilient stiffening members so that resilient force may be applied by the skier to the toe portion of the foot by bending the knees forward against the resilient member.
In the telemark skiing style, it is important that a wide range of flexibility be maintained between the rear of the foot and the toe of the foot since telemarking has similarities to walking. Typical telemark boots or shoes comprise a leather article of footwear having a forward toe hinge that mounts in a front binding of a relatively narrow ski. The rear of the boot is not secured to the ski so that the user may hend the boot along an area adjacent the ball of the foot. Indeed, for competent telemarking, it is necessary that the pivotal relationship between the toe and the heel of the foot exceed the typical range of flexing movement that takes place during walking.
One problem with telemark boots, however, has been their inability to resist torsional rotation about a longitudinal axis and their inability to resist lateral motion of the heel. This problem was recognized in U.S. Pat. No. 4,505,056 issued 19 Mar. 1985 to Beneteau. The Beneteau patent addresses the problem by providing a cross-country ski boot having a plurality of weakening ribs that extend adjacent the ball of the foot across the sides and top thereof. To allow the boot to pivot, Beneteau encases his boot in a relatively stiff shell having a front toe portion and a rear heel portion separated and interconnected by a flat, flexing region of the rigid shell. The shell is then pivotally attached to a ski binding so as to prevent torsional rotation and lateral movement of the heel.
In addition to the prior art devices noted above, many other inventors have recognized the lack of comfort generated by an inflexible alpine boot when the skier removes the skis and attempts to walk from one location to another. To this end, there have been numerous developments of ski boots which flex slightly to allow greater ease in walking. One such prior art device is shown in U.S. Pat. No. 3,972,134 to Kastinger wherein a boot having a stiff sole and a rigid upper shell includes regions of reduced strength at a fore part of the foot to allow bending of the foot forwardly of the ankle, and pleats are provided at a forward part of the ankle to facilitate walking. U.S. Pat. No. 3,535,800, issued 27 Oct. 1970 to Stohr, shows a ski boot that flexes about a pivot on the ankle with this flexing accomplished by baffles extending forwardly and rearwardly of the boot at the ankle region.
U.S. Pat. No. 3,953,930, issued 4 May 1976 to Ramer, also discloses a ski boot designed for greater ease in walking. In the Ramer structure, a flexible sole is provided to support a rigid shell defining a heel portion and a forward foot portion being telescopically inserted into the rigid shell defining a toe portion for the boot. As the skier walks in this boot, the toe portion and the heel/foot portion telescope with respect to one another. Limit stop means for preventing hyperextension of the floating toe Portion is Provided to limit relative movement between the toe portion and the heel portion.
Many of these problems were addressed in our earlier application, as noted above, wherein we disclosed an article of footwear having a pivotal toe structure. In this device, independent toe and heel portions are relatively pivotally rotatable with respect to one another over a fairly large angular range. The toe and heel portions are hinged together to form the foot enclosure and pivot to allow relative ease in walking and to permit rotational movement in telemarking. At the same time, the hinging is accomplished in a manner that restricts relative torsional rotation so that the ski boot may be used for alpine skiing.
The combination of these two skiing styles has traditionally been performed by only the most capable and dedicated of skiers because of the difficulty in making parallel turns in conventional telemarking boots. However, if a boot as contemplated above were available, such style combinations would most undoubtedly become more popular, perhaps extremely so, since the enhanced ability to make parallel turns in such a boot would put he sport within the reach oil the average skier. Moreover, it is expected that skiers would readily take to the sport because it would provide them with another way of skiing and thereby add more variety to the already popular sport.
Despite the improvements of these prior art patents over earlier ski boots, there still remains a need for a ski boot that may be employed for both alpine and telemark style skiing. There is a particular need for a ski boot which may remain locked in both the front and rear bindings of a ski boot which is structured so that the heel portion pivots or rotates about the ball of the foot while at the same time remaining rigid against torsional rotation and lateral movement of the heel portion. Such a boot's resistance to rotation and lateral movement would make it much easier for the telemarking skier to make and control traditional "alpine style" parallel turns.